// WBI signature algorithm for Bilibili API
// https://github.com/SocialSisterYi/bilibili-API-collect/blob/master/docs/misc/sign/wbi.md

const MIXIN_KEY_ENC_TAB = [
  46,47,18,2,53,8,23,32,15,50,10,31,58,3,45,35,
  27,43,5,49,33,9,42,19,29,28,14,39,12,38,41,13,
  37,48,7,16,24,55,40,61,26,17,0,1,60,51,30,4,
  22,25,54,21,56,59,6,63,57,62,11,36,20,34,44,52,
];

function getMixinKey(imgKey: string, subKey: string): string {
  const raw = imgKey + subKey;
  return MIXIN_KEY_ENC_TAB.slice(0, 32).map(i => raw[i]).join('');
}

// Minimal MD5 implementation (no dependencies)
function md5(input: string): string {
  function safeAdd(x: number, y: number) { const lsw=(x&0xffff)+(y&0xffff); const msw=(x>>16)+(y>>16)+(lsw>>16); return (msw<<16)|(lsw&0xffff); }
  function bitRotateLeft(num: number, cnt: number) { return (num<<cnt)|(num>>>(32-cnt)); }
  function md5cmn(q:number,a:number,b:number,x:number,s:number,t:number){return safeAdd(bitRotateLeft(safeAdd(safeAdd(a,q),safeAdd(x,t)),s),b);}
  function md5ff(a:number,b:number,c:number,d:number,x:number,s:number,t:number){return md5cmn((b&c)|(~b&d),a,b,x,s,t);}
  function md5gg(a:number,b:number,c:number,d:number,x:number,s:number,t:number){return md5cmn((b&d)|(c&~d),a,b,x,s,t);}
  function md5hh(a:number,b:number,c:number,d:number,x:number,s:number,t:number){return md5cmn(b^c^d,a,b,x,s,t);}
  function md5ii(a:number,b:number,c:number,d:number,x:number,s:number,t:number){return md5cmn(c^(b|~d),a,b,x,s,t);}

  function md5blks(s: string): number[] {
    const nblk = ((s.length+8)>>6)+1;
    const blks = new Array(nblk*16).fill(0);
    for(let i=0;i<s.length;i++) blks[i>>2]|=s.charCodeAt(i)<<((i%4)*8);
    blks[s.length>>2]|=0x80<<((s.length%4)*8);
    blks[nblk*16-2]=s.length*8;
    return blks;
  }

  const x = md5blks(input);
  let a=1732584193,b=-271733879,c=-1732584194,d=271733878;
  for(let i=0;i<x.length;i+=16){
    const [aa,bb,cc,dd]=[a,b,c,d];
    a=md5ff(a,b,c,d,x[i+0],7,-680876936);d=md5ff(d,a,b,c,x[i+1],12,-389564586);c=md5ff(c,d,a,b,x[i+2],17,606105819);b=md5ff(b,c,d,a,x[i+3],22,-1044525330);
    a=md5ff(a,b,c,d,x[i+4],7,-176418897);d=md5ff(d,a,b,c,x[i+5],12,1200080426);c=md5ff(c,d,a,b,x[i+6],17,-1473231341);b=md5ff(b,c,d,a,x[i+7],22,-45705983);
    a=md5ff(a,b,c,d,x[i+8],7,1770035416);d=md5ff(d,a,b,c,x[i+9],12,-1958414417);c=md5ff(c,d,a,b,x[i+10],17,-42063);b=md5ff(b,c,d,a,x[i+11],22,-1990404162);
    a=md5ff(a,b,c,d,x[i+12],7,1804603682);d=md5ff(d,a,b,c,x[i+13],12,-40341101);c=md5ff(c,d,a,b,x[i+14],17,-1502002290);b=md5ff(b,c,d,a,x[i+15],22,1236535329);
    a=md5gg(a,b,c,d,x[i+1],5,-165796510);d=md5gg(d,a,b,c,x[i+6],9,-1069501632);c=md5gg(c,d,a,b,x[i+11],14,643717713);b=md5gg(b,c,d,a,x[i+0],20,-373897302);
    a=md5gg(a,b,c,d,x[i+5],5,-701558691);d=md5gg(d,a,b,c,x[i+10],9,38016083);c=md5gg(c,d,a,b,x[i+15],14,-660478335);b=md5gg(b,c,d,a,x[i+4],20,-405537848);
    a=md5gg(a,b,c,d,x[i+9],5,568446438);d=md5gg(d,a,b,c,x[i+14],9,-1019803690);c=md5gg(c,d,a,b,x[i+3],14,-187363961);b=md5gg(b,c,d,a,x[i+8],20,1163531501);
    a=md5gg(a,b,c,d,x[i+13],5,-1444681467);d=md5gg(d,a,b,c,x[i+2],9,-51403784);c=md5gg(c,d,a,b,x[i+7],14,1735328473);b=md5gg(b,c,d,a,x[i+12],20,-1926607734);
    a=md5hh(a,b,c,d,x[i+5],4,-378558);d=md5hh(d,a,b,c,x[i+8],11,-2022574463);c=md5hh(c,d,a,b,x[i+11],16,1839030562);b=md5hh(b,c,d,a,x[i+14],23,-35309556);
    a=md5hh(a,b,c,d,x[i+1],4,-1530992060);d=md5hh(d,a,b,c,x[i+4],11,1272893353);c=md5hh(c,d,a,b,x[i+7],16,-155497632);b=md5hh(b,c,d,a,x[i+10],23,-1094730640);
    a=md5hh(a,b,c,d,x[i+13],4,681279174);d=md5hh(d,a,b,c,x[i+0],11,-358537222);c=md5hh(c,d,a,b,x[i+3],16,-722521979);b=md5hh(b,c,d,a,x[i+6],23,76029189);
    a=md5hh(a,b,c,d,x[i+9],4,-640364487);d=md5hh(d,a,b,c,x[i+12],11,-421815835);c=md5hh(c,d,a,b,x[i+15],16,530742520);b=md5hh(b,c,d,a,x[i+2],23,-995338651);
    a=md5ii(a,b,c,d,x[i+0],6,-198630844);d=md5ii(d,a,b,c,x[i+7],10,1126891415);c=md5ii(c,d,a,b,x[i+14],15,-1416354905);b=md5ii(b,c,d,a,x[i+5],21,-57434055);
    a=md5ii(a,b,c,d,x[i+12],6,1700485571);d=md5ii(d,a,b,c,x[i+3],10,-1894986606);c=md5ii(c,d,a,b,x[i+10],15,-1051523);b=md5ii(b,c,d,a,x[i+1],21,-2054922799);
    a=md5ii(a,b,c,d,x[i+8],6,1873313359);d=md5ii(d,a,b,c,x[i+15],10,-30611744);c=md5ii(c,d,a,b,x[i+6],15,-1560198380);b=md5ii(b,c,d,a,x[i+13],21,1309151649);
    a=md5ii(a,b,c,d,x[i+4],6,-145523070);d=md5ii(d,a,b,c,x[i+11],10,-1120210379);c=md5ii(c,d,a,b,x[i+2],15,718787259);b=md5ii(b,c,d,a,x[i+9],21,-343485551);
    a=safeAdd(a,aa);b=safeAdd(b,bb);c=safeAdd(c,cc);d=safeAdd(d,dd);
  }

  function hex(n: number) { return ('0'+(n&0xff).toString(16)).slice(-2)+('0'+((n>>8)&0xff).toString(16)).slice(-2)+('0'+((n>>16)&0xff).toString(16)).slice(-2)+('0'+((n>>24)&0xff).toString(16)).slice(-2); }
  return hex(a)+hex(b)+hex(c)+hex(d);
}

export function signWbi(
  params: Record<string, string | number>,
  imgKey: string,
  subKey: string,
): Record<string, string | number> {
  const mixinKey = getMixinKey(imgKey, subKey);
  const wts = Math.floor(Date.now() / 1000);
  const all: Record<string, string | number> = { ...params, wts };
  const query = Object.keys(all)
    .sort()
    .map(k => {
      const v = String(all[k]).replace(/[!'()*]/g, '');
      return `${k}=${v}`;
    })
    .join('&');
  const w_rid = md5(query + mixinKey);
  return { ...all, w_rid };
}